Process Control of an Alternating Aerobic-Anoxic Sequencing Batch Reactor for Nitrogen Removal via Nitrite
Process Control of an Alternating Aerobic-Anoxic Sequencing Batch Reactor for Nitrogen Removal via Nitrite
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DOI：
10.1002/ceat.200700468
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发表时间：
2008-04
影响因子：
2.1
通讯作者：
W. Zeng;Yongzhen Peng;Shu-ying Wang;C. Peng
中科院分区：
文献类型：
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作者：
W. Zeng;Yongzhen Peng;Shu-ying Wang;C. Peng
亚硝酸盐脱氮技术是一种新型的脱氮技术，由于其节省了亚硝酸盐脱氮所需的曝气能量和亚硝酸盐脱氮所需的外部碳源，因此在工程应用中越来越受欢迎。采用序批式活性污泥法（SBR），采用交替好氧-缺氧（AAA）运行模式，对进水碱度不足的工业废水进行脱氮处理，实现亚硝酸盐短程硝化.结果表明，硝化过程中pH随时间变化的在线监测，可以判断碱度是否充足，何时氨氮被完全氧化。在进水碱度不足的情况下，AAA工艺降低了外加碱度和碳源投加量，改善了出水水质，氨氮浓度低于检测限。在随后的缺氧反硝化期间，可以恢复之前在好氧硝化过程中消耗的碱度的一半。如果交替好氧/缺氧循环重复两次以上，则当pH降低0.4-0.5时，第一硝化循环停止。当pH下降0.8-1.0时，中间硝化作用终止，最终硝化作用持续时间受pH剖面上溶解氧（DO）断点和氨谷控制。每个缺氧反硝化的时间尺度由氧化还原电位（ORP）曲线上的硝酸盐拐点和pH曲线上的硝酸盐顶点决定。与传统的SBR工艺相比，具有实时控制策略的AAA工艺在进水碱度不足的条件下，脱氮效率提高到97%以上。此外，通过亚硝酸盐实现脱氮，亚硝酸盐积累率在95%以上。
Nitrogen removal via nitrite is a novel technology and is becoming popular for engineering applications since it results in a saving of the aeration energy required for nitritation and external carbon sources for denitritation. An alternating aerobic-anoxic (AAA) operational pattern was applied in a sequencing batch reactor (SBR) process to improve the nitrogen removal efficiency and achieve partial nitrification via nitrite from industrial wastewater with influent alkalinity deficiencies. The results showed that the online monitoring of the pH-time variations during nitrification could indicate if the alkalinity was sufficient and when the ammonia nitrogen was completely oxidized. Under conditions of deficient influent alkalinity, the AAA process reduced the external alkalinity and the carbon sources addition and improved the effluent quality with ammonia nitrogen concentration below the detection limits. Half of the alkalinity previously consumed during aerobic nitrification could be recovered during the subsequent anoxic denitrification period. If the cycles of alternating aerobic/anoxic were repeated more than twice, the first nitrification cycle was stopped when the pH decreased by 0.4–0.5. The middle nitrification was terminated when the pH decreased by 0.8–1.0, and the final nitrification duration was controlled by the dissolved oxygen (DO) breakpoint and ammonia valley on the pH profile. Each anoxic time-scale for denitrification was determined by the nitrate knee on the oxidation-reduction potential (ORP) profile and the nitrate apex on the pH profiles. In comparison to the conventional SBR process, the AAA process with a real-time control strategy resulted in an improved nitrogen removal efficiency of greater than 97 % under conditions of deficient influent alkalinity. Moreover, nitrogen removal via nitrite was achieved with a nitrite accumulation rate above 95 %.